The present invention is directed to air distribution system for HVAC equipment, and more particularly, to a method and apparatus for providing individual comfort control by minimizing the size of the air distribution zones.
The temperature of an air conditioned environment is generally modulated by an HVAC and air distribution system based upon data provided by a zone sensor. The zone sensor data typically includes operating mode, setpoint, and actual temperature. The zone sensor is positioned in the environment to be controlled at a locale representative of the overall environment. Invariably, this results in discomfort for some occupants of the zone, including those occupants located in peripheral areas. In fact, studies have documented that 50% of a building's occupants are uncomfortable about 50% of the time regardless of their location or the building's HVAC design. These occupants perceive the conditioned air as either too warm or too cold even when the building setpoints are consistently maintained.
Additionally, the use of modular furniture such as movable half-walls for office environments can seriously disrupt airflow patterns within an environment. This modular furniture forms barriers to airflow, thereby creating nonhomogeneous temperature conditions in the form of heat or cold concentrations.
U.S. Pat. No. 4,135,440 to Schmidt et al. attempts to provide a solution to this problem by connecting a riser tube to a supply air point to thereby direct supply air through the riser tube to a discharge head supported by the riser tube. The discharge head has a structure which causes the supply air to fan out in a cone over an occupant at a work station. However, riser (or drop) tubes in a work environment are obstructive, unsightly, and costly. Additionally, this patent is not amenable to providing conditioned air differing in temperature from the supply air, and fails to provide any automatic control over airflow. Also, there are very limited retrofit applications for this type of patent.